blob: f914b26cf0c2efdfac05b8af9e6d9b8a37124dfc [file] [log] [blame]
Gerd Hoffmannab315232010-12-14 18:40:46 +00001/******************************************************************************
2 * gntdev.c
3 *
4 * Device for accessing (in user-space) pages that have been granted by other
5 * domains.
6 *
7 * Copyright (c) 2006-2007, D G Murray.
8 * (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#undef DEBUG
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/init.h>
25#include <linux/miscdevice.h>
26#include <linux/fs.h>
27#include <linux/mm.h>
28#include <linux/mman.h>
29#include <linux/mmu_notifier.h>
30#include <linux/types.h>
31#include <linux/uaccess.h>
32#include <linux/sched.h>
33#include <linux/spinlock.h>
34#include <linux/slab.h>
Daniel De Graafaab8f112011-02-03 12:19:02 -050035#include <linux/highmem.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000036
37#include <xen/xen.h>
38#include <xen/grant_table.h>
Daniel De Graafca47cea2011-03-09 18:07:34 -050039#include <xen/balloon.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000040#include <xen/gntdev.h>
Daniel De Graafbdc612d2011-02-03 12:19:04 -050041#include <xen/events.h>
Gerd Hoffmannab315232010-12-14 18:40:46 +000042#include <asm/xen/hypervisor.h>
43#include <asm/xen/hypercall.h>
44#include <asm/xen/page.h>
45
46MODULE_LICENSE("GPL");
47MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
48 "Gerd Hoffmann <kraxel@redhat.com>");
49MODULE_DESCRIPTION("User-space granted page access driver");
50
Daniel De Graafef910822011-02-03 12:18:59 -050051static int limit = 1024*1024;
Gerd Hoffmannab315232010-12-14 18:40:46 +000052module_param(limit, int, 0644);
Daniel De Graafef910822011-02-03 12:18:59 -050053MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
54 "the gntdev device");
55
56static atomic_t pages_mapped = ATOMIC_INIT(0);
Gerd Hoffmannab315232010-12-14 18:40:46 +000057
Daniel De Graafaab8f112011-02-03 12:19:02 -050058static int use_ptemod;
59
Gerd Hoffmannab315232010-12-14 18:40:46 +000060struct gntdev_priv {
61 struct list_head maps;
Gerd Hoffmannab315232010-12-14 18:40:46 +000062 /* lock protects maps from concurrent changes */
63 spinlock_t lock;
64 struct mm_struct *mm;
65 struct mmu_notifier mn;
66};
67
Daniel De Graafbdc612d2011-02-03 12:19:04 -050068struct unmap_notify {
69 int flags;
70 /* Address relative to the start of the grant_map */
71 int addr;
72 int event;
73};
74
Gerd Hoffmannab315232010-12-14 18:40:46 +000075struct grant_map {
76 struct list_head next;
Gerd Hoffmannab315232010-12-14 18:40:46 +000077 struct vm_area_struct *vma;
78 int index;
79 int count;
80 int flags;
Daniel De Graaf68b025c2011-02-03 12:19:01 -050081 atomic_t users;
Daniel De Graafbdc612d2011-02-03 12:19:04 -050082 struct unmap_notify notify;
Gerd Hoffmannab315232010-12-14 18:40:46 +000083 struct ioctl_gntdev_grant_ref *grants;
84 struct gnttab_map_grant_ref *map_ops;
85 struct gnttab_unmap_grant_ref *unmap_ops;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +000086 struct page **pages;
Gerd Hoffmannab315232010-12-14 18:40:46 +000087};
88
Daniel De Graafaab8f112011-02-03 12:19:02 -050089static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
90
Gerd Hoffmannab315232010-12-14 18:40:46 +000091/* ------------------------------------------------------------------ */
92
93static void gntdev_print_maps(struct gntdev_priv *priv,
94 char *text, int text_index)
95{
96#ifdef DEBUG
97 struct grant_map *map;
98
Daniel De Graafef910822011-02-03 12:18:59 -050099 pr_debug("%s: maps list (priv %p)\n", __func__, priv);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000100 list_for_each_entry(map, &priv->maps, next)
101 pr_debug(" index %2d, count %2d %s\n",
102 map->index, map->count,
103 map->index == text_index && text ? text : "");
104#endif
105}
106
107static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
108{
109 struct grant_map *add;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000110 int i;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000111
112 add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
113 if (NULL == add)
114 return NULL;
115
116 add->grants = kzalloc(sizeof(add->grants[0]) * count, GFP_KERNEL);
117 add->map_ops = kzalloc(sizeof(add->map_ops[0]) * count, GFP_KERNEL);
118 add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL);
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000119 add->pages = kzalloc(sizeof(add->pages[0]) * count, GFP_KERNEL);
120 if (NULL == add->grants ||
121 NULL == add->map_ops ||
122 NULL == add->unmap_ops ||
123 NULL == add->pages)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000124 goto err;
125
Daniel De Graafca47cea2011-03-09 18:07:34 -0500126 if (alloc_xenballooned_pages(count, add->pages))
127 goto err;
128
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000129 for (i = 0; i < count; i++) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500130 add->map_ops[i].handle = -1;
131 add->unmap_ops[i].handle = -1;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000132 }
133
Gerd Hoffmannab315232010-12-14 18:40:46 +0000134 add->index = 0;
135 add->count = count;
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500136 atomic_set(&add->users, 1);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000137
Gerd Hoffmannab315232010-12-14 18:40:46 +0000138 return add;
139
140err:
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000141 kfree(add->pages);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000142 kfree(add->grants);
143 kfree(add->map_ops);
144 kfree(add->unmap_ops);
145 kfree(add);
146 return NULL;
147}
148
149static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
150{
151 struct grant_map *map;
152
153 list_for_each_entry(map, &priv->maps, next) {
154 if (add->index + add->count < map->index) {
155 list_add_tail(&add->next, &map->next);
156 goto done;
157 }
158 add->index = map->index + map->count;
159 }
160 list_add_tail(&add->next, &priv->maps);
161
162done:
Gerd Hoffmannab315232010-12-14 18:40:46 +0000163 gntdev_print_maps(priv, "[new]", add->index);
164}
165
166static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
167 int index, int count)
168{
169 struct grant_map *map;
170
171 list_for_each_entry(map, &priv->maps, next) {
172 if (map->index != index)
173 continue;
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500174 if (count && map->count != count)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000175 continue;
176 return map;
177 }
178 return NULL;
179}
180
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500181static void gntdev_put_map(struct grant_map *map)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000182{
183 if (!map)
184 return;
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000185
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500186 if (!atomic_dec_and_test(&map->users))
187 return;
188
189 atomic_sub(map->count, &pages_mapped);
190
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500191 if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
192 notify_remote_via_evtchn(map->notify.event);
193 }
194
Daniel De Graafaab8f112011-02-03 12:19:02 -0500195 if (map->pages) {
196 if (!use_ptemod)
197 unmap_grant_pages(map, 0, map->count);
198
Daniel De Graafca47cea2011-03-09 18:07:34 -0500199 free_xenballooned_pages(map->count, map->pages);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500200 }
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000201 kfree(map->pages);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000202 kfree(map->grants);
203 kfree(map->map_ops);
204 kfree(map->unmap_ops);
205 kfree(map);
206}
207
208/* ------------------------------------------------------------------ */
209
210static int find_grant_ptes(pte_t *pte, pgtable_t token,
211 unsigned long addr, void *data)
212{
213 struct grant_map *map = data;
214 unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500215 int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000216 u64 pte_maddr;
217
218 BUG_ON(pgnr >= map->count);
Jeremy Fitzhardingeba5d1012010-12-08 10:54:32 -0800219 pte_maddr = arbitrary_virt_to_machine(pte).maddr;
220
Daniel De Graafaab8f112011-02-03 12:19:02 -0500221 gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000222 map->grants[pgnr].ref,
223 map->grants[pgnr].domid);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500224 gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500225 -1 /* handle */);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000226 return 0;
227}
228
229static int map_grant_pages(struct grant_map *map)
230{
231 int i, err = 0;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500232
233 if (!use_ptemod) {
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500234 /* Note: it could already be mapped */
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500235 if (map->map_ops[0].handle != -1)
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500236 return 0;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500237 for (i = 0; i < map->count; i++) {
Ian Campbell38eaeb02011-03-08 16:56:43 +0000238 unsigned long addr = (unsigned long)
Daniel De Graafaab8f112011-02-03 12:19:02 -0500239 pfn_to_kaddr(page_to_pfn(map->pages[i]));
240 gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
241 map->grants[i].ref,
242 map->grants[i].domid);
243 gnttab_set_unmap_op(&map->unmap_ops[i], addr,
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500244 map->flags, -1 /* handle */);
Daniel De Graafaab8f112011-02-03 12:19:02 -0500245 }
246 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000247
248 pr_debug("map %d+%d\n", map->index, map->count);
Stefano Stabellinia12b4eb2010-12-10 14:56:42 +0000249 err = gnttab_map_refs(map->map_ops, map->pages, map->count);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000250 if (err)
251 return err;
252
253 for (i = 0; i < map->count; i++) {
254 if (map->map_ops[i].status)
255 err = -EINVAL;
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500256 else {
257 BUG_ON(map->map_ops[i].handle == -1);
258 map->unmap_ops[i].handle = map->map_ops[i].handle;
259 pr_debug("map handle=%d\n", map->map_ops[i].handle);
260 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000261 }
262 return err;
263}
264
Daniel De Graafb57c1862011-02-09 15:12:00 -0500265static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000266{
267 int i, err = 0;
268
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500269 if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
270 int pgno = (map->notify.addr >> PAGE_SHIFT);
Daniel De Graaf0ea22f02011-02-08 09:14:06 -0500271 if (pgno >= offset && pgno < offset + pages && use_ptemod) {
Daniel De Graaff4ee4af2011-02-23 08:11:36 -0500272 void __user *tmp = (void __user *)
273 map->vma->vm_start + map->notify.addr;
Daniel De Graaf9960be92011-02-09 18:15:50 -0500274 err = copy_to_user(tmp, &err, 1);
275 if (err)
Dan Carpenter12f02582011-03-19 08:44:34 +0300276 return -EFAULT;
Daniel De Graaf0ea22f02011-02-08 09:14:06 -0500277 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
278 } else if (pgno >= offset && pgno < offset + pages) {
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500279 uint8_t *tmp = kmap(map->pages[pgno]);
280 tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
281 kunmap(map->pages[pgno]);
282 map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
283 }
284 }
285
Daniel De Graaf0ea22f02011-02-08 09:14:06 -0500286 err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, pages);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000287 if (err)
288 return err;
289
290 for (i = 0; i < pages; i++) {
291 if (map->unmap_ops[offset+i].status)
292 err = -EINVAL;
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500293 pr_debug("unmap handle=%d st=%d\n",
294 map->unmap_ops[offset+i].handle,
295 map->unmap_ops[offset+i].status);
296 map->unmap_ops[offset+i].handle = -1;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000297 }
298 return err;
299}
300
Daniel De Graafb57c1862011-02-09 15:12:00 -0500301static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
302{
303 int range, err = 0;
304
305 pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
306
307 /* It is possible the requested range will have a "hole" where we
308 * already unmapped some of the grants. Only unmap valid ranges.
309 */
310 while (pages && !err) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500311 while (pages && map->unmap_ops[offset].handle == -1) {
Daniel De Graafb57c1862011-02-09 15:12:00 -0500312 offset++;
313 pages--;
314 }
315 range = 0;
316 while (range < pages) {
Daniel De Graaf77c35ac2011-02-23 08:11:35 -0500317 if (map->unmap_ops[offset+range].handle == -1) {
Daniel De Graafb57c1862011-02-09 15:12:00 -0500318 range--;
319 break;
320 }
321 range++;
322 }
323 err = __unmap_grant_pages(map, offset, range);
324 offset += range;
325 pages -= range;
326 }
327
328 return err;
329}
330
Gerd Hoffmannab315232010-12-14 18:40:46 +0000331/* ------------------------------------------------------------------ */
332
Daniel De Graafd79647a2011-03-07 15:18:57 -0500333static void gntdev_vma_open(struct vm_area_struct *vma)
334{
335 struct grant_map *map = vma->vm_private_data;
336
337 pr_debug("gntdev_vma_open %p\n", vma);
338 atomic_inc(&map->users);
339}
340
Gerd Hoffmannab315232010-12-14 18:40:46 +0000341static void gntdev_vma_close(struct vm_area_struct *vma)
342{
343 struct grant_map *map = vma->vm_private_data;
344
Daniel De Graafd79647a2011-03-07 15:18:57 -0500345 pr_debug("gntdev_vma_close %p\n", vma);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000346 map->vma = NULL;
347 vma->vm_private_data = NULL;
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500348 gntdev_put_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000349}
350
Gerd Hoffmannab315232010-12-14 18:40:46 +0000351static struct vm_operations_struct gntdev_vmops = {
Daniel De Graafd79647a2011-03-07 15:18:57 -0500352 .open = gntdev_vma_open,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000353 .close = gntdev_vma_close,
Gerd Hoffmannab315232010-12-14 18:40:46 +0000354};
355
356/* ------------------------------------------------------------------ */
357
358static void mn_invl_range_start(struct mmu_notifier *mn,
359 struct mm_struct *mm,
360 unsigned long start, unsigned long end)
361{
362 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
363 struct grant_map *map;
364 unsigned long mstart, mend;
365 int err;
366
367 spin_lock(&priv->lock);
368 list_for_each_entry(map, &priv->maps, next) {
369 if (!map->vma)
370 continue;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000371 if (map->vma->vm_start >= end)
372 continue;
373 if (map->vma->vm_end <= start)
374 continue;
375 mstart = max(start, map->vma->vm_start);
376 mend = min(end, map->vma->vm_end);
377 pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n",
378 map->index, map->count,
379 map->vma->vm_start, map->vma->vm_end,
380 start, end, mstart, mend);
381 err = unmap_grant_pages(map,
382 (mstart - map->vma->vm_start) >> PAGE_SHIFT,
383 (mend - mstart) >> PAGE_SHIFT);
384 WARN_ON(err);
385 }
386 spin_unlock(&priv->lock);
387}
388
389static void mn_invl_page(struct mmu_notifier *mn,
390 struct mm_struct *mm,
391 unsigned long address)
392{
393 mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
394}
395
396static void mn_release(struct mmu_notifier *mn,
397 struct mm_struct *mm)
398{
399 struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
400 struct grant_map *map;
401 int err;
402
403 spin_lock(&priv->lock);
404 list_for_each_entry(map, &priv->maps, next) {
405 if (!map->vma)
406 continue;
407 pr_debug("map %d+%d (%lx %lx)\n",
408 map->index, map->count,
409 map->vma->vm_start, map->vma->vm_end);
410 err = unmap_grant_pages(map, /* offset */ 0, map->count);
411 WARN_ON(err);
412 }
413 spin_unlock(&priv->lock);
414}
415
416struct mmu_notifier_ops gntdev_mmu_ops = {
417 .release = mn_release,
418 .invalidate_page = mn_invl_page,
419 .invalidate_range_start = mn_invl_range_start,
420};
421
422/* ------------------------------------------------------------------ */
423
424static int gntdev_open(struct inode *inode, struct file *flip)
425{
426 struct gntdev_priv *priv;
427 int ret = 0;
428
429 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
430 if (!priv)
431 return -ENOMEM;
432
433 INIT_LIST_HEAD(&priv->maps);
434 spin_lock_init(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000435
Daniel De Graafaab8f112011-02-03 12:19:02 -0500436 if (use_ptemod) {
437 priv->mm = get_task_mm(current);
438 if (!priv->mm) {
439 kfree(priv);
440 return -ENOMEM;
441 }
442 priv->mn.ops = &gntdev_mmu_ops;
443 ret = mmu_notifier_register(&priv->mn, priv->mm);
444 mmput(priv->mm);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000445 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000446
447 if (ret) {
448 kfree(priv);
449 return ret;
450 }
451
452 flip->private_data = priv;
453 pr_debug("priv %p\n", priv);
454
455 return 0;
456}
457
458static int gntdev_release(struct inode *inode, struct file *flip)
459{
460 struct gntdev_priv *priv = flip->private_data;
461 struct grant_map *map;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000462
463 pr_debug("priv %p\n", priv);
464
465 spin_lock(&priv->lock);
466 while (!list_empty(&priv->maps)) {
467 map = list_entry(priv->maps.next, struct grant_map, next);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500468 list_del(&map->next);
469 gntdev_put_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000470 }
471 spin_unlock(&priv->lock);
472
Daniel De Graafaab8f112011-02-03 12:19:02 -0500473 if (use_ptemod)
474 mmu_notifier_unregister(&priv->mn, priv->mm);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000475 kfree(priv);
476 return 0;
477}
478
479static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
480 struct ioctl_gntdev_map_grant_ref __user *u)
481{
482 struct ioctl_gntdev_map_grant_ref op;
483 struct grant_map *map;
484 int err;
485
486 if (copy_from_user(&op, u, sizeof(op)) != 0)
487 return -EFAULT;
488 pr_debug("priv %p, add %d\n", priv, op.count);
489 if (unlikely(op.count <= 0))
490 return -EINVAL;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000491
492 err = -ENOMEM;
493 map = gntdev_alloc_map(priv, op.count);
494 if (!map)
495 return err;
Daniel De Graafef910822011-02-03 12:18:59 -0500496
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500497 if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
498 pr_debug("can't map: over limit\n");
499 gntdev_put_map(map);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000500 return err;
501 }
502
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500503 if (copy_from_user(map->grants, &u->refs,
504 sizeof(map->grants[0]) * op.count) != 0) {
505 gntdev_put_map(map);
Daniel De Graafef910822011-02-03 12:18:59 -0500506 return err;
507 }
508
Gerd Hoffmannab315232010-12-14 18:40:46 +0000509 spin_lock(&priv->lock);
510 gntdev_add_map(priv, map);
511 op.index = map->index << PAGE_SHIFT;
512 spin_unlock(&priv->lock);
513
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500514 if (copy_to_user(u, &op, sizeof(op)) != 0)
515 return -EFAULT;
516
Gerd Hoffmannab315232010-12-14 18:40:46 +0000517 return 0;
518}
519
520static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
521 struct ioctl_gntdev_unmap_grant_ref __user *u)
522{
523 struct ioctl_gntdev_unmap_grant_ref op;
524 struct grant_map *map;
525 int err = -ENOENT;
526
527 if (copy_from_user(&op, u, sizeof(op)) != 0)
528 return -EFAULT;
529 pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
530
531 spin_lock(&priv->lock);
532 map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500533 if (map) {
534 list_del(&map->next);
535 gntdev_put_map(map);
536 err = 0;
537 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000538 spin_unlock(&priv->lock);
Gerd Hoffmannab315232010-12-14 18:40:46 +0000539 return err;
540}
541
542static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
543 struct ioctl_gntdev_get_offset_for_vaddr __user *u)
544{
545 struct ioctl_gntdev_get_offset_for_vaddr op;
Daniel De Graafa8792112011-02-03 12:19:00 -0500546 struct vm_area_struct *vma;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000547 struct grant_map *map;
548
549 if (copy_from_user(&op, u, sizeof(op)) != 0)
550 return -EFAULT;
551 pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
552
Daniel De Graafa8792112011-02-03 12:19:00 -0500553 vma = find_vma(current->mm, op.vaddr);
554 if (!vma || vma->vm_ops != &gntdev_vmops)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000555 return -EINVAL;
Daniel De Graafa8792112011-02-03 12:19:00 -0500556
557 map = vma->vm_private_data;
558 if (!map)
559 return -EINVAL;
560
Gerd Hoffmannab315232010-12-14 18:40:46 +0000561 op.offset = map->index << PAGE_SHIFT;
562 op.count = map->count;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000563
564 if (copy_to_user(u, &op, sizeof(op)) != 0)
565 return -EFAULT;
566 return 0;
567}
568
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500569static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
570{
571 struct ioctl_gntdev_unmap_notify op;
572 struct grant_map *map;
573 int rc;
574
575 if (copy_from_user(&op, u, sizeof(op)))
576 return -EFAULT;
577
578 if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
579 return -EINVAL;
580
581 spin_lock(&priv->lock);
582
583 list_for_each_entry(map, &priv->maps, next) {
584 uint64_t begin = map->index << PAGE_SHIFT;
585 uint64_t end = (map->index + map->count) << PAGE_SHIFT;
586 if (op.index >= begin && op.index < end)
587 goto found;
588 }
589 rc = -ENOENT;
590 goto unlock_out;
591
592 found:
Daniel De Graaf9960be92011-02-09 18:15:50 -0500593 if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
594 (map->flags & GNTMAP_readonly)) {
595 rc = -EINVAL;
596 goto unlock_out;
597 }
598
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500599 map->notify.flags = op.action;
600 map->notify.addr = op.index - (map->index << PAGE_SHIFT);
601 map->notify.event = op.event_channel_port;
602 rc = 0;
603 unlock_out:
604 spin_unlock(&priv->lock);
605 return rc;
606}
607
Gerd Hoffmannab315232010-12-14 18:40:46 +0000608static long gntdev_ioctl(struct file *flip,
609 unsigned int cmd, unsigned long arg)
610{
611 struct gntdev_priv *priv = flip->private_data;
612 void __user *ptr = (void __user *)arg;
613
614 switch (cmd) {
615 case IOCTL_GNTDEV_MAP_GRANT_REF:
616 return gntdev_ioctl_map_grant_ref(priv, ptr);
617
618 case IOCTL_GNTDEV_UNMAP_GRANT_REF:
619 return gntdev_ioctl_unmap_grant_ref(priv, ptr);
620
621 case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
622 return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
623
Daniel De Graafbdc612d2011-02-03 12:19:04 -0500624 case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
625 return gntdev_ioctl_notify(priv, ptr);
626
Gerd Hoffmannab315232010-12-14 18:40:46 +0000627 default:
628 pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
629 return -ENOIOCTLCMD;
630 }
631
632 return 0;
633}
634
635static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
636{
637 struct gntdev_priv *priv = flip->private_data;
638 int index = vma->vm_pgoff;
639 int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
640 struct grant_map *map;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500641 int i, err = -EINVAL;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000642
643 if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
644 return -EINVAL;
645
646 pr_debug("map %d+%d at %lx (pgoff %lx)\n",
647 index, count, vma->vm_start, vma->vm_pgoff);
648
649 spin_lock(&priv->lock);
650 map = gntdev_find_map_index(priv, index, count);
651 if (!map)
652 goto unlock_out;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500653 if (use_ptemod && map->vma)
Gerd Hoffmannab315232010-12-14 18:40:46 +0000654 goto unlock_out;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500655 if (use_ptemod && priv->mm != vma->vm_mm) {
Gerd Hoffmannab315232010-12-14 18:40:46 +0000656 printk(KERN_WARNING "Huh? Other mm?\n");
657 goto unlock_out;
658 }
659
Daniel De Graaf68b025c2011-02-03 12:19:01 -0500660 atomic_inc(&map->users);
661
Gerd Hoffmannab315232010-12-14 18:40:46 +0000662 vma->vm_ops = &gntdev_vmops;
663
Daniel De Graafd79647a2011-03-07 15:18:57 -0500664 vma->vm_flags |= VM_RESERVED|VM_DONTEXPAND;
665
666 if (use_ptemod)
667 vma->vm_flags |= VM_DONTCOPY|VM_PFNMAP;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000668
669 vma->vm_private_data = map;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000670
Daniel De Graafaab8f112011-02-03 12:19:02 -0500671 if (use_ptemod)
672 map->vma = vma;
673
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500674 if (map->flags) {
675 if ((vma->vm_flags & VM_WRITE) &&
676 (map->flags & GNTMAP_readonly))
Dan Carpentera93e20a2011-03-19 08:45:43 +0300677 goto out_unlock_put;
Daniel De Graaf12996fc2011-02-09 16:11:32 -0500678 } else {
679 map->flags = GNTMAP_host_map;
680 if (!(vma->vm_flags & VM_WRITE))
681 map->flags |= GNTMAP_readonly;
682 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000683
Daniel De Graaff0a70c82011-01-07 11:51:47 +0000684 spin_unlock(&priv->lock);
685
Daniel De Graafaab8f112011-02-03 12:19:02 -0500686 if (use_ptemod) {
687 err = apply_to_page_range(vma->vm_mm, vma->vm_start,
688 vma->vm_end - vma->vm_start,
689 find_grant_ptes, map);
690 if (err) {
691 printk(KERN_WARNING "find_grant_ptes() failure.\n");
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500692 goto out_put_map;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500693 }
Gerd Hoffmannab315232010-12-14 18:40:46 +0000694 }
695
696 err = map_grant_pages(map);
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500697 if (err)
698 goto out_put_map;
Daniel De Graaff0a70c82011-01-07 11:51:47 +0000699
Daniel De Graafaab8f112011-02-03 12:19:02 -0500700 if (!use_ptemod) {
701 for (i = 0; i < count; i++) {
702 err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
703 map->pages[i]);
704 if (err)
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500705 goto out_put_map;
Daniel De Graafaab8f112011-02-03 12:19:02 -0500706 }
707 }
708
Daniel De Graaff0a70c82011-01-07 11:51:47 +0000709 return 0;
710
Gerd Hoffmannab315232010-12-14 18:40:46 +0000711unlock_out:
712 spin_unlock(&priv->lock);
713 return err;
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500714
Dan Carpentera93e20a2011-03-19 08:45:43 +0300715out_unlock_put:
716 spin_unlock(&priv->lock);
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500717out_put_map:
Daniel De Graaf84e40752011-02-09 15:11:59 -0500718 if (use_ptemod)
719 map->vma = NULL;
Daniel De Graaf90b6f302011-02-03 14:16:54 -0500720 gntdev_put_map(map);
721 return err;
Gerd Hoffmannab315232010-12-14 18:40:46 +0000722}
723
724static const struct file_operations gntdev_fops = {
725 .owner = THIS_MODULE,
726 .open = gntdev_open,
727 .release = gntdev_release,
728 .mmap = gntdev_mmap,
729 .unlocked_ioctl = gntdev_ioctl
730};
731
732static struct miscdevice gntdev_miscdev = {
733 .minor = MISC_DYNAMIC_MINOR,
734 .name = "xen/gntdev",
735 .fops = &gntdev_fops,
736};
737
738/* ------------------------------------------------------------------ */
739
740static int __init gntdev_init(void)
741{
742 int err;
743
744 if (!xen_domain())
745 return -ENODEV;
746
Daniel De Graafaab8f112011-02-03 12:19:02 -0500747 use_ptemod = xen_pv_domain();
748
Gerd Hoffmannab315232010-12-14 18:40:46 +0000749 err = misc_register(&gntdev_miscdev);
750 if (err != 0) {
751 printk(KERN_ERR "Could not register gntdev device\n");
752 return err;
753 }
754 return 0;
755}
756
757static void __exit gntdev_exit(void)
758{
759 misc_deregister(&gntdev_miscdev);
760}
761
762module_init(gntdev_init);
763module_exit(gntdev_exit);
764
765/* ------------------------------------------------------------------ */